Conventionally, as an article storage device of this kind, one as shown in FIG. 14 is known. The article storage device 70 includes pushers 73 arranged respectively in two article passages 72 formed in an article rack 71. A large number of articles S are stored in the article passages 72 in a manner placed one behind another in a horizontal row in a front-rear direction each in an upright position, between each of the pushers 73 and a transparent stopper 74 arranged on a front side of the article rack 71. The pushers 73 are mounted to the article rack 71 such that each pusher 73 is movable in the front-rear direction, and urged by a spiral spring, not shown, arranged at a rear end of the article rack 71 to constantly press on the articles S from a rear side of the article rack 71. Each pusher 73 is connected to the spiral spring by way of a flat belt, not shown. The flat belt has one end thereof connected to the spiral spring, and extends such that it reaches a front end of the article rack 71 and then makes a U-turn to extend rearward to have the other end thereof connected to the pusher 73. During a vending operation for vending an article S, the stopper 74 is pivotally moved to open the article passage 72, whereby a foremost one of the articles S is pushed forward from the article passage 72 by the pressing load of the pusher 73 to dispense the same for vending.
At a predetermined position of each flat belt, there is formed a hole, not shown, while the article rack 71 has switches, neither of which is shown, each having a lever engageable with the hole. These switches and holes constitute part of a detecting device for detecting whether articles S are sold out. When all the articles in one of the article passages 72 are sold out and the corresponding pusher 73 has reached its extreme forward position, the lever is engaged with the hole of the flat belt to turn on the switch, thereby detecting that the articles S are sold out.
In the article storage device 70 constructed as above, the pressing load of the pusher 73 is basically sufficient if it has a magnitude required for smoothly moving all the articles S stored in the article passage 72. On the other hand, according to the conventional article storage device 70 described above, the spiral spring is used as means by which the pusher 73 obtains the urging force for pressing on the articles S. Spiral springs generally have a characteristic that the urging forces thereof are not largely changed with respect to a stroke thereof. Therefore, as shown by a dotted line in FIG. 13, even if the number of articles stored in the article passage 72 is decreased, the pressing load of the pusher 73 for pressing on the articles S is not sharply reduced.
As a result, even when the articles S received in the article passage 72 are considerably decreased in number, an excessively large pressing load which makes little difference from a pressing load applied when a lot of articles S are stored in the article passage 72 is applied to the articles S. Therefore, if containers for the articles S are made of soft materials, deformation or breakage thereof can be caused, resulting in spoiled commercial values of the articles. For the same reason, when the number of articles S stored in the article passage 72 is considerably decreased, the total frictional resistance of the articles S is decreased, and hence the moving speed of the articles S during a dispensing operation becomes very high. This causes an article S to be dispensed with a large force, thereby causing the above deformation or breakage or incapability of a normal execution of the vending operation. Further, since each spiral spring is arranged at the rear end of the article rack, the effective storage length of the article passage 72 is reduced by space in which the spiral spring is arranged.
Further, the detecting device for detecting whether the articles S are sold out is comprised of switches or the like provided separately from the article rack 71. Hence, a separate space exclusively provided for the detecting device is required. In addition, since the detecting device is configured such that the lever of each switch is engaged with a hole formed in a long flat belt, the lever can be hindered from being engaged with the hole in the flat belt due to inaccurate location of the hole or stretching of the flat belt caused by use thereof. In such a case, it is impossible to detect whether the articles S are sold out.